add toggling between front/rear camera

app/src/main/java/com/simplemobiletools/camera/MainActivity.java

@@ -37,7 +37,13 @@ public class MainActivity extends AppCompatActivity {
 
     @OnClick(R.id.toggle_camera)
     public void toggleCamera() {
+        if (currCamera == Camera.CameraInfo.CAMERA_FACING_BACK)
+            currCamera = Camera.CameraInfo.CAMERA_FACING_FRONT;
+        else
+            currCamera = Camera.CameraInfo.CAMERA_FACING_BACK;
 
+        preview.releaseCamera();
+        preview.setCamera(currCamera);
     }
 
     @OnClick(R.id.shutter)
@@ -53,8 +59,7 @@ public class MainActivity extends AppCompatActivity {
         if (cnt == 1) {
             toggleCameraBtn.setVisibility(View.INVISIBLE);
         }
-        Camera camera = Camera.open(currCamera);
+        preview.setCamera(currCamera);
-        preview.setCamera(camera);
     }
 
     @Override

app/src/main/java/com/simplemobiletools/camera/PhotoProcessor.java

@@ -4,6 +4,7 @@ import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.graphics.Matrix;
+import android.hardware.Camera;
 import android.media.ExifInterface;
 import android.media.MediaScannerConnection;
 import android.os.AsyncTask;
@@ -19,10 +20,12 @@ import java.util.Date;
 
 public class PhotoProcessor extends AsyncTask<byte[], Void, Void> {
     private static final String TAG = PhotoProcessor.class.getSimpleName();
-    private static Context context;
+    private static Context mContext;
+    private static int mCameraId;
 
-    public PhotoProcessor(Context cxt) {
+    public PhotoProcessor(Context context, int cameraId) {
-        context = cxt;
+        mContext = context;
+        mCameraId = cameraId;
     }
 
     @Override
@@ -51,7 +54,7 @@ public class PhotoProcessor extends AsyncTask<byte[], Void, Void> {
     }
 
     private static File getOutputMediaFile() {
-        final String appName = context.getResources().getString(R.string.app_name);
+        final String appName = mContext.getResources().getString(R.string.app_name);
         final File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), appName);
 
         if (!mediaStorageDir.exists()) {
@@ -67,21 +70,28 @@ public class PhotoProcessor extends AsyncTask<byte[], Void, Void> {
     private Bitmap setBitmapRotation(Bitmap bitmap, String path) throws IOException {
         final ExifInterface exif = new ExifInterface(path);
         final String orientation = exif.getAttribute(ExifInterface.TAG_ORIENTATION);
+
+        float angle = 0f;
         if (orientation.equalsIgnoreCase("6")) {
-            bitmap = rotateImage(bitmap, 90);
+            angle = 90;
         } else if (orientation.equalsIgnoreCase("8")) {
-            bitmap = rotateImage(bitmap, 270);
+            angle = 270;
         } else if (orientation.equalsIgnoreCase("3")) {
-            bitmap = rotateImage(bitmap, 180);
+            angle = 180;
         } else if (orientation.equalsIgnoreCase("0")) {
-            bitmap = rotateImage(bitmap, 90);
+            angle = 90;
         }
-        return bitmap;
+        return rotateImage(bitmap, angle);
     }
 
     public static Bitmap rotateImage(Bitmap source, float angle) {
         final Matrix matrix = new Matrix();
         matrix.postRotate(angle);
+
+        final Camera.CameraInfo info = Utils.getCameraInfo(mCameraId);
+        if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT)
+            matrix.preScale(-1.f, 1.f);
+
         return Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(), matrix, true);
     }
 
@@ -100,6 +110,6 @@ public class PhotoProcessor extends AsyncTask<byte[], Void, Void> {
 
     private void scanPhoto(File photo) {
         final String[] photoPath = {photo.getAbsolutePath()};
-        MediaScannerConnection.scanFile(context, photoPath, null, null);
+        MediaScannerConnection.scanFile(mContext, photoPath, null, null);
     }
 }

app/src/main/java/com/simplemobiletools/camera/Preview.java

@@ -1,11 +1,13 @@
 package com.simplemobiletools.camera;
 
+import android.app.Activity;
 import android.content.Context;
 import android.graphics.Rect;
 import android.hardware.Camera;
 import android.os.Handler;
 import android.util.Log;
 import android.view.MotionEvent;
+import android.view.Surface;
 import android.view.SurfaceHolder;
 import android.view.SurfaceView;
 import android.view.View;
@@ -26,23 +28,28 @@ public class Preview extends ViewGroup implements SurfaceHolder.Callback, View.O
     private static SurfaceView surfaceView;
     private static Camera.Size previewSize;
     private static boolean canTakePicture;
+    private static Activity activity;
+    private static int currCameraId;
 
-    public Preview(Context cxt) {
+    public Preview(Context context) {
-        super(cxt);
+        super(context);
     }
 
-    public Preview(Context cxt, SurfaceView sv) {
+    public Preview(Activity act, SurfaceView sv) {
-        super(cxt);
+        super(act);
 
+        activity = act;
         surfaceView = sv;
         surfaceHolder = surfaceView.getHolder();
         surfaceHolder.addCallback(this);
         surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
-        canTakePicture = true;
+        canTakePicture = false;
         surfaceView.setOnTouchListener(this);
     }
 
-    public void setCamera(Camera newCamera) {
+    public void setCamera(int cameraId) {
+        currCameraId = cameraId;
+        final Camera newCamera = Camera.open(cameraId);
         if (camera == newCamera) {
             return;
         }
@@ -55,12 +62,53 @@ public class Preview extends ViewGroup implements SurfaceHolder.Callback, View.O
             requestLayout();
 
             final Camera.Parameters params = camera.getParameters();
-            params.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
+            final List<String> focusModes = params.getSupportedFocusModes();
+            if (focusModes.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE))
+                params.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
+
             camera.setParameters(params);
-            camera.setDisplayOrientation(90);
+            setCameraDisplayOrientation(cameraId, camera);
+
+            if (canTakePicture) {
+                try {
+                    camera.setPreviewDisplay(surfaceHolder);
+                } catch (IOException e) {
+                    Log.e(TAG, "setCamera " + e.getMessage());
+                }
+                setupPreview();
+            }
         }
     }
 
+    public static void setCameraDisplayOrientation(int cameraId, android.hardware.Camera camera) {
+        final Camera.CameraInfo info = Utils.getCameraInfo(cameraId);
+        int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
+        int degrees = 0;
+        switch (rotation) {
+            case Surface.ROTATION_0:
+                degrees = 0;
+                break;
+            case Surface.ROTATION_90:
+                degrees = 90;
+                break;
+            case Surface.ROTATION_180:
+                degrees = 180;
+                break;
+            case Surface.ROTATION_270:
+                degrees = 270;
+                break;
+        }
+
+        int result;
+        if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
+            result = (info.orientation + degrees) % 360;
+            result = (360 - result) % 360;
+        } else {
+            result = (info.orientation - degrees + 360) % 360;
+        }
+        camera.setDisplayOrientation(result);
+    }
+
     public void takePicture() {
         if (canTakePicture) {
             camera.takePicture(null, null, takePictureCallback);
@@ -74,12 +122,15 @@ public class Preview extends ViewGroup implements SurfaceHolder.Callback, View.O
             new Handler().postDelayed(new Runnable() {
                 @Override
                 public void run() {
-                    camera.startPreview();
+                    if (camera != null)
+                        camera.startPreview();
+
                     canTakePicture = true;
                 }
             }, PHOTO_PREVIEW_LENGTH);
 
-            new PhotoProcessor(getContext()).execute(data);
+            final Camera.CameraInfo info = Utils.getCameraInfo(currCameraId);
+            new PhotoProcessor(getContext(), info.facing).execute(data);
         }
     };
 
@@ -101,7 +152,10 @@ public class Preview extends ViewGroup implements SurfaceHolder.Callback, View.O
             @Override
             public void onAutoFocus(boolean success, Camera camera) {
                 camera.cancelAutoFocus();
-                parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
+                final List<String> focusModes = parameters.getSupportedFocusModes();
+                if (focusModes.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE))
+                    parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
+
                 camera.setParameters(parameters);
             }
         });
@@ -134,7 +188,7 @@ public class Preview extends ViewGroup implements SurfaceHolder.Callback, View.O
     public void surfaceCreated(SurfaceHolder holder) {
         try {
             if (camera != null) {
-                camera.setPreviewDisplay(holder);
+                camera.setPreviewDisplay(surfaceHolder);
             }
         } catch (IOException e) {
             Log.e(TAG, "surfaceCreated IOException " + e.getMessage());
@@ -143,6 +197,11 @@ public class Preview extends ViewGroup implements SurfaceHolder.Callback, View.O
 
     @Override
     public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
+        setupPreview();
+    }
+
+    private void setupPreview() {
+        canTakePicture = true;
         if (camera != null) {
             final Camera.Parameters parameters = camera.getParameters();
             parameters.setPreviewSize(previewSize.width, previewSize.height);

app/src/main/java/com/simplemobiletools/camera/Utils.java

@@ -0,0 +1,11 @@
+package com.simplemobiletools.camera;
+
+import android.hardware.Camera;
+
+public class Utils {
+    public static Camera.CameraInfo getCameraInfo(int cameraId) {
+        final Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
+        Camera.getCameraInfo(cameraId, info);
+        return info;
+    }
+}